a throwback uniform based on their 1929 uniforms when they won their first NFL championship. The throwbacks are as accurate as possible while complying with current NFL guidelines, with a brown modern-shell helmet in place of the leather helmets of 1929, along with blue jerseys and gold circles with the jersey numbers nested within the circles, and brown pants. Like throwbacks worn in recent seasons by the San Diego Chargers, Dallas Cowboys, Buffalo Bills, New York Jets, and the archrival Minnesota Vikings, these throwbacks will be a permanent addition to the Packers uniforms, unlike throwbacks worn by the Detroit Lions and Pittsburgh Steelers that were intended as one-time deals but made permanent, as well as several one-shot throwbacks in recent years. The new Packers throwbacks replace the previous throwbacks (which comprised the current helmets with the "G" logo and stripes removed, white jerseys with plain green lettering, and tan pants) worn sporadically since the early 2000s (decade). Also going the throwback route were the Chicago Bears, who harkened back to the Sid Luckman era with a 1940s set, replacing the pumpkin orange third jerseys, and the Indianapolis Colts, who will wear throwbacks as well. Since the Colts only have two colors, they only have previously worn a throwback jersey once in their history, in . The difference between the 2004 throwback and the 2010 throwback is the helmet color, which reverses the 2004 scheme. The Arizona Cardinals, who were the only team to not wear a third jersey in any form since the NFL allowed third jerseys in , unveiled a black third jersey to be worn in 2010. The Philadelphia Eagles have adopted their championship uniforms that were worn September 12 against the Packers, the team they beat to win their last championship in celebration of the 50th anniversary of that game. The Tennessee Titans returned to using navy blue jerseys as their third jersey, after a one-year hiatus in which they wore light blue Houston Oilers throwback jerseys in celebration of the 50th anniversary of the American Football League, but did not wear them for any game in 2010. The Pittsburgh Steelers wore their throwbacks against the Cleveland Browns on October 17 and against the New England Patriots on November 14. The Seattle Seahawks have retired the neon green uniform worn for one game in against Chicago, which was in turn an offshoot from an April Fools' Day